Journal of Geological Society of India (Online archive from Vol 1 to Vol 78)

D. Srinivasa Sarma ¹, Janet Muhling ², M. Ram Mohan ¹, Neal McNaughton ³

Affiliations
1 National Geophysical Research lnstitute, Uppal Road, Hyderabad-500007, IN
2 Centre for Microscopy and Microanalysis, University of Western Australia, 35, Stirling Highway, Crawley, 6009, IN
3 Centre for Exploration Targeting, University of Western Australia, 35, Stiriling Highway, Crawley 6009, IN

Abstract

We report here, for the first time, the occurrence of hydrothermal monazite and xenotime in alteration haloes associated with the gold-Mineralized zones of the Hutti Gold Deposit in Karnataka, India. These minerals were identified by systematic scanning of polished thin sections in an SEM using backscattered electron and energy dispersive X-Ray detectors. Most of the grains are very small (<10 μm), although some larger gram (30-40 μm) have also been identified Hydrothermal monazite and xenotime, though volumetrically minor, have been found to be important components in many orogenic gold deposits in Australia, Canada, Brazil and South Africa,as they form a part of the primary ore mineral assemblage, elther in ore-Bearing veins itself or are intergrown wlth ore minerals in wallrock alteration zones. Both monazite and xenotime are excellent geochronometers, and their importance is that they allow precise ages to be obtained for gold mineralization events. The discovery of these minerals in hydrothermally altered rocks from the Hutti gold deposit Dharwar Craton enables us to estimate the age of gold mineralization event(s).

Keywords

Hutti Gold Deposit, Alteration Zones, Hydrothermal Minerals, Monazite, Xenotime, Karnataka.

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